基于Web和OPC技术的远程监控系统的研究

在分析基于COM/DCOM的OPC技术应用于工业控制的不足基础上,提出一种基于Web和OPC技术的远程监控系统的实现方法.首先给出了基于Web和OPC技术的远程监控系统的总体架构,接着深入研究了远程监控系统OPC服务器和Web服务器的实现技术,并给出具体的实现方案.提出的实现方案在汽车换档器远程测试系统中得到了验证.     

基于OPC XML-DA技术的远程监控系统的设计

针对目前OPC(Object Linking and Embedding Process Control)组态软件大多只限于本地的监视和控制的情况,通过采用基于Web服务的OPC XML-DA新技术,设计了远程监控系统,使得远程用户可以使用浏览嚣或定制的客户端通过互联网或局域网实现对现场的远程监控.由于采用了标准的OPC接口和Web服务调用接口,方便了系统的扩展和升级.该系统已在变电站监控系统中成功地应用,结果证明,它满足了用户对远程监视和控制的需求.     

基于OPC技术的FF总线远程监控

OPC是一种应用于控制领域的开放式工业标准。通过OPC服务器访问过程数据,上层应用可以不关心底层的硬件特性以及OPC服务器与硬件通讯细节,就可以获得工业现场发送的数据。本文对基于H1总线的OPC服务器与客户程序进行了开发,经调试运行证明其工作良好,实现了对H1总线段的远程监控。     

OPC技术应用于工业测试系统的研究

管理人员通过网络远程监控整个工业测试过程是技术发展的必然趋势。基于丁业标准OPC技术及其应用于工业测试系统的优势，给出了远程测试系统的总体方案，具体分析了OPC服务器、OPC客户程序的实现方法，介绍了基于OPC技术实现远程监控与测试的方法。在基于OPC技术的换档器远程测试系统中得到了验证，这种测试方法弥补了当前测试系统的不足。     

异构网络下的Web监控系统设计研究

针对基于Web的工业信息监控系统的实现,着重研究了控制网络与信息网络之间的数据交换和数据的Web动态发布技术.借鉴基于DCOM的分布式系统设计方式,采用OPC数据交换技术来实现工业现场控制网络与企业信息网络之间的数据共享,并提出了OPC客户端以ActiveX控件的形式在浏览器中与现场监控系统进行数据交换的方案,不但实现了异构网络之间的数据共享,而且改善了传统的以数据库为中心的Web监控解决方案所带来的实时性差等缺点.     

基于OPC技术的电网监控系统RTDB的设计与实现

实时数据库系统能够很好地实现对过程监控系统中的数据管理、交换和共享。该文通过研究现有的实时数据库技术和当前最流行的工业标准接口OPC技术，设计了支持OPC标准的实时数据库系统方案，并根据电网监控系统的实际需要，初步实现了一个实时数据库系统平台，应用开发可以使用该数据库系统COM控件创建任何需要实时数据库支持的监控系统。测试表明该系统能够满足农电网监控系统对数据实时处理的要求。     

基于OPC-XML技术的互联网实时监控系统研究

讨论了基于OPC-XML技术和ASP技术的Web应用。根据OPC-XML纲要，设计并实现了基于OPC-XML技术的互联网实时监控系统。Internet／Intranet用户可以通过Web浏览器从Web服务器得到现场的实时数据，了解现场的实际情况；也可以按照各种方式处理这些实时数据，从而实现了基于Internet／Intranet的远程监控、远程故障诊断、远程指挥调度和远程设备管理。     

基于OPC XML-DA技术的远程监控系统研究

本文基于OPC XML-DA技术,开发了一套针对工业现场远程监控的OPC XML-DA服务端和客户端软件。该系统主要利用Web Service技术,结合.NET框架,将现有的OPC DA服务器转换成OPC XML-DA服务器,同时利用ADO.NET技术将OPC XML-DA服务器中的获取到的数据转存到SQL Server数据库中,并利用GridView控件显示给用户,从而完成了本系统的开发。     

基于OPC XML-DA技术的远程监控系统研究

本文基于OPC XML-DA技术,开发了一套针对工业现场远程监控的OPC XML-DA服务端和客户端软件。该系统主要利用Web Service技术,结合.NET框架,将现有的OPC DA服务器转换成OPC XML-DA服务器,同时利用ADO.NET技术将OPC XML-DA服务器中的获取到的数据转存到SQL Server数据库中,并利用GridView控件显示给用户,从而完成了本系统的开发。     

OPC XML-DA网关的设计与实现

为了促进工厂数据跨平台、跨层次交换的要求,OPC基金会制定并发布了基于Web服务技术的0PC XML—DA接口规范。通过设计并实现的OPC XML—DA中间层网关,可以完成对现有的基于OPC COM接口规范的工业数据的XML化工作,很方便地实现了现存的基于COM技术的OPCDA服务器的升级,使得这两种接口可以和谐地共存。     

煤矿井下安全监控分站的设计及其仿真实现

为了设计一种具有低成本、低功耗、易操作、功能强且可靠性高的煤矿井下安全分站,针对煤矿安全生产实际,文章提出了采用MCS-51系列单片机为核心、具有CAN总线通信接口的煤矿井下安全监控分站的设计方案;首先给出煤矿井下安全监控分站的整体构架设计,然后着重阐述模拟量输入信号处理系统的设计过程,最后说明单片机最小系统及其键盘、显示、报警、通信等各个组成部分的设计;为验证设计方案的可行性与有效性,使用Proteus软件对设计内容进行仿真验证,设计的煤矿井下安全监控分站具有瓦斯、温度等模拟量参数超标报警功能和电机开停、风门开闭等开关量指示功能;仿真结果表明:设计的煤矿井下安全监控分站具有一定的实际应用价值.     

View-based model-driven architecture for enhancing maintainability of data access services

In modern service-oriented architectures, database access is done by a special type of services, the so-called data access services (DAS). Though, particularly in data-intensive applications, using and developing DAS are very common today, the link between the DAS and their implementation, e.g. a layer of data access objects (DAOs) encapsulating the database queries, still is not sufficiently elaborated, yet. As a result, as the number of DAS grows, finding the desired DAS for reuse and/or associated documentation can become an impossible task. In this paper we focus on bridging this gap between the DAS and their implementation by presenting a view-based, model-driven data access architecture (VMDA) managing models of the DAS, DAOs and database queries in a queryable manner. Our models support tailored views of different stakeholders and are scalable with all types of DAS implementations. In this paper we show that our view-based and model driven architecture approach can enhance software development productivity and maintainability by improving DAS documentation. Moreover, our VMDA opens a wide range of applications such as evaluating DAS usage for DAS performance optimization. Furthermore, we provide tool support and illustrate the applicability of our VMDA in a large-scale case study. Finally, we quantitatively prove that our approach performs with acceptable response times.     

A pragmatic multi-method investigation of discrepant technological events: Coping,attributions, and ‘accidental’ learning

Discrepant technological events or situations that entail a problem, a misunderstanding or a difficulty with the Information Technology (IT) being employed, are common in the workplace, and can lead to frustration and avoidance behaviors. Little is known, however, about how individuals cope with these events. This paper examines these events by using a multi-method pragmatic approach informed by coping theory. The results of two studies – a critical incident study and an experiment – serve to build and test, respectively, a theoretical model that posits that individuals use a variety of strategies when dealing with these events: they experience negative emotions, make external attributions, and adopt engagement coping strategies directed at solving the event, eventually switching to a disengagement coping strategy when they feel they have no control over the situation. Furthermore, users’ efforts may result in ‘accidental’ learning as they try to overcome the discrepant IT events through engagement coping. The paper ends with a discussion of the results in light of existing literature, future opportunities for research, and implications for practice.     

The Distributed Time-Triggered Simulation Scheme: Core Principles and Supporting Execution Engine

Distributed real-time simulation is a young technology field but its practice is under increasing demands. In recent years the author and his collaborators have been establishing a new approach called the distributed time-triggered simulation (DTS) scheme which is conceptually simple and easy to use but widely applicable. The concept was initiated in the course of developing a new-generation object-oriented real-time programming scheme called the time-triggered message-triggered object (TMO) programming scheme. Some fundamental issues inherent in distributed real-time simulation that were learned during recent experimental studies are discussed along with some approaches for resolving the issues. An execution engine developed to support both the TMOs engaged in control computation and the TMOs engaged in DTS is also discussed along with its possible extensions that will enable significantly larger-scale DTSs.     

Software-Konfigurationsmanagement in großen Softwareprojekten

Zusammenfassung Mit zunehmender Größe der Softwaresysteme verschärfen sich die für die Software-Herstellung typischen Probleme: Beherrschen großer Objektmengen, Erhalten der Systemkonsistenz, Kontrolle der ständigen Änderungseinflüsse und Gewährleisten einer langen Lebensdauer. Die Disziplin Konfigurationsmanagement bildet den methodischen Ansatz, diese Probleme besser zu beherrschen. Software-Konfigurationsmanagement faßt die Herstellung von Softwaresystemen als eine Abfolge von kontrollierten Änderungen an gesicherten Zwischen- und Endergebnissen auf. Dargestellt werden die Objekte und Funktionen des Software-Konfigurationsmanagements sowie die hierfür in großen Software-Projekten benötigten Methoden, Instanzen und Hilfsmittel.     

Information for Authors

正http://www.zju.edu.cn/jzus http://www.springerlink.com Aim The Journals of Zhejiang University-SCIENCE(A/B/C)are edited by the international board of distinguished Chinese and foreign scientists,and are aimed to present the latest developments and achievements in scientific research in China and     

Editorial:Brain-machine interface(BMI) and cyborg intelligence

正Brain-machine interfaces(BMIs)aim at building a direct communication pathway between the brain and an external device,and represent an area of research where significant progress has been made during the past decade.Based on BMIs,mind information can be read out by neural signals to control     

Information for Authors

正http://www.zju.edu.cn/jzus http://www.springerlink.com Aim The Journals of Zhejiang University-SCIENCE(A/B/C)are edited by the international board of distinguished Chinese and foreign scientists,and are aimed to present the latest developments and achievements in scientific research in China and overseas to the world’s scientific circles,especially to stimulate     

SCIENCE CHINA Information Sciences SUBJECT INDEX TO VOLUME 57(2014)

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Information for Authors

正http://www.zju.edu.cn/jzus http://www.springerlink.com Aim The Journals of Zhejiang University-SCIENCE(A/B/C)are edited by the international board of distinguished Chinese and foreign scientists,and are aimed to present the latest developments and achievements in scientific research in China and overseas to the world’s scientific circles,especially to stimulate